Mother gives birth to two sets of twins despite using two different types of contraceptive

Mother Emma Power's first pregnancy happened against the odds, with the York-local giving birth to twin boys, despite taking the contraceptive pill.

Determined not to have the same thing happen again, Power opted to get an implant – but ended up falling pregnant again five years later, this time with twin girls.

According to Power, 30, doctors blamed the happy accidents on couple's abnormally high fertility.

"The doctors said that I must be incredibly fertile and if we just relied on contraceptives again, then I was likely to fall pregnant with yet another multiple birth," Power told MailOnline.

Power's first pregnancy happened when she was a 19-year-old university student, soon after meeting her husband, John.

"It was a complete surprise when I found out I was pregnant," she said. "I had been taking the Pill for a while and thought there was no way that I could possibly fall pregnant. I made sure I took it each day, and I hadn't been ill."

Power gave birth to Connor and Kyle, who are now 10-years-old, certain that would be the last time she had twins.

But, five years on, history repeated.

According to Power, her husband didn't believe she was pregnant with two children again, until he was shown a scan with two heartbeats.

Despite the initial shock, the couple happily welcomed Jessica and Ruby into the world in 2013.

According to England's National Health Service, the odds of having two sets of non-identical twins while on contraceptive is one in three billion.

The pair decided to undergo a sterilisation and vasectomy, no longer feeling as though they could trust contraceptives.

"We couldn’t risk having yet another set of twins," Power said.

But, even though Power fell pregnant in rather unlikely circumstances, she's considers herself lucky.

"I do feel very lucky to have my two sets of twins," she said. "Even if they were a complete surprise."